Electromagnetic device



Feb 114, 1950 H. J. FHNDLEY 394979402 ELECTROMAGNETIC DEVICE Filed Aug. 26, 1946 UVVENTDR.

HOWflQOdLRMZMfY BY WWWW 7 ATTORNEYS Patented Feb. 14, 1950 ELECTROMAGNETIC DEVICE Howard J. Findley, Chardon, Ohio, assignor to Eaton Manufacturing Company,

Cleveland,

Ohio, a corporation of Ohio Application August 26, 1946, Serial No. 693,061

2 Claims.

This invention relates to electromagnetic power transmitting devices and more particularly to novel structural features thereof.

Broadly the invention comprehends a provision of electromagnetic power transmitting devices of the eddy current type whereas the energizing coils of the devices are supplied current directly at a point approximating the axis of the devices.

Heretofore in the construction of eddy current electromagnetic power transmitting devices it has been the general practice to provide slip rings as a means for supplying current to the energizing coils thereof. The instant invention through the incorporation of structural refinements in the construction of power transmitting devices of this type eliminates the use of slip rings and as such provides a more direct, effective and economical means of supplying current from a source of electrical power to the energizing coils of the devices.

An object of the invention is the provision of an eddy current electromagnetic power transmitting device having means for supplying current to the energizing coil thereof without the necessity of employing costly slip rings.

Another object of the invention is the provision of an eddy current electromagnetic power transmitting device of simplified construction and economical cost.

A further object of the invention is the provision of an eddy current electromagnetic power transmitting device of high operating efficiency having means incorporated therein providing for the efiective supply of current to the energizing coil through brushes located near the axis of the I contacting rotating portions of the device.

Other objects andadvantages of the invention will appear from the following description taken in connection with the drawings, forming a part of the specification; and in which:

Figure 1 is a fragmentary cross sectional view of an eddy current electromagnetic power transmitting device embodying novel structural features, and

Figure 2 is a cross sectional view taken along line 2--'2 Figure 1.

Although numerous eddy current electromagnetic power transmitting devices have been devised and manufactured over a period of a great many years no practical structure has heretofore been devised employing other than slip rings in association with current supplied brushes for the purpose of delivering current to the energizing coils of the devices. By the provision of current supply means as taught by the instant invention wherein the current supplied brushes arelocated at or near the axis of the device in direct contact with rotating parts of the power transmitting devices, slip rings are eliminated, thus reducing the overall production cost of the devices, as well as affording a shorter more direct and effective path of fiow of current from the brushes to the energizing coils of the devices. The power transmitting device herein devised is of the type shown by Patent No. 2,367,163 to Martin P. Winther, dated January 9, 1945.

Referring to the drawings for more specific details of the invention l represents generally an eddy current electromagnetic power transmitting device comprising a drum member i2, driven from a suitable motive source by the belt [4 received by a grooved pulley l5 fixedly secured upon the hub l8 of the drum, and a cooperating rotor mounted and fixedly secured internally of the drum i2 upon a driven output shaft 22. The drum is supported for rotation upon a pair of bearings 24 and '26 disposed axially on opposite sides of the rotor upon shaft 22, the open end of the drum having a cover plate 28 secured therein by a snap ring 30, said cover plate having a hub section 32 journaled upon the bearing 26 for supporting the drum in its rotation relative to the shaft.

The rotor 20 consists of a pair of identical annular members 34 and 36 of cross sectional U shape fixedly mounted in adjacent relationship upon an enlarged portion 38 of shaft 22 and providing therebetween an annular space for the reception of a ring shaped energizing coil 40. The members 34 and 36 forming the field body of the power transmitting device are each provided with pole arms axially extended in alternately overlapping relation externally of the coil 40, said arms at their periphery being spaced from the internal annular surface of the drums by a predetermined amount.

The shaft 22 has provided in one end 42 thereof a central bore 44 for the reception of an annular ring 46 supporting a contact button 48 I connected to one end 50 of the coil 40, said coil wire extending from the coil through an opening 52 in member 34 thence through an opening 54 in the surface of the shaft communicating with a bore 56 forming a part of bore 44 in the shaft. The other end 58 of the coil extends therefrom through an opening 60 in member 34 and is soldered or otherwise fixedly secured upon the exterior of member 34 to provide a contact therewith for the purpose of completing the current flow circuit, said flow from this end of the coil a bearing 68 supported on shaft 22. The brush E2 is supportedfor-axial movement in a square cage 10 extending into the bore 44 of the shaft upon:

an extension of the axis line of the device and' shaft 22, said cage being mounted uponbut-inv sulated from the housing 66. A flexible'lead H from the brush 62 is connected tora terminal bolt 12 secured in the insulation:13;said terminalbe ing adapted to be connected to a power line from a storage battery or other. source of electric current. The brush 64 is mounted for radial movement in a hollowed out plug 14 thfadabTy adjustable in housing 66 providing the ground terminal of the coil 4!] whereas the housing 56'- isadapted to remain stationary in fixedly assent bledtpositionupon the apparatus-with which the device is-adaptedto be associated. The electricalcurrentcircuit for the device and coil-thereof is thus-made-from the body of the apparatus, not

shown, as a'transmittingagent back tothe other terminal of-the current-sourceso as to make a complete circuit from the coil: through the medium-yof -the brushes-t2 and 64, contact button 48 and shaft 22 to-the source of electrical current.

:Although-the brush 64 ishereinabove defined-as specifically relatedto the -coil 4t as a ground terminal .-thereof, said brush cansimilarly to brush 2 also bea current-supplied or hot brush fonthe coil vas the use might so'warrant. Furthermoreait-is to be readily realizedcthat brush 64 can be assembled in asimilar manner'to brush 52 I but-at the opposite endof shaftZZ thereby plac- 3 ingboth brushes in approximately the same axial;

zone relative --to the drive. fl-

.-:It-.is.to be noted-in view of the structure as shown and described that the shortestmost direct path-of current flow-is attained thus providing f iorirthe effective energization-ofthe-coil while atmthe same. :time presenting an economical structure throughthe elimination of more costly slip rings ordinarily employed in the power transmitting -device of this type.-. 2-

e a a Thexelectrom-agnetic device although herein specifically shown as a powerztransmitting device orwdrive can readily-beadaptedfor use as anelectromagneticbrake or the like'and accordingly the: illustration madeis "not tobe taken as a 4 limitation of invention.

.Whileth-is invention has been described in connection witha' certain specific embodiments, the

principle involved is susceptible ofnumerous other applications that will readily occur to persons skilled in the art.- The invention,therefore, is limited only as indicated by the scope of the-appended claims.

What I claim is:

1. An electromagnetic device comprising a rotatable member, a second rotatable member associated therewith, an electromagnet carried by one of the members, a shaft secured to the member carrying the electromagnet, said electromagnet having leads at the respective ends thereof, one d, be ns eql red to he .r teiah gm m on which 'the'inagnetis carried and the other lead being insulatingly supported in the shaft with its terminus lying upon the axis of the shaft, a stationary current supply axially spring pressed brushextending along the axis of the shaft havmg contacting association with the coil lead supported -in the shaftjat 'its terminus, a second stabituary current-supply axially spring pressed brushe'xten'dingperpendicularly to the axis of the shaft having contacting relation upon the outer periphery of the shaft and a housing journalled on'thes'haft supporting the brushes for current conducting engagement respectively with the term-inusbf'one 'lead from the 'coil" and with "the shaft:, g .-."V---..

2. An electromagnetic device comprising a rotatable member; a' second rotatable "member "associated therewith,-an-electromagnet carried by one of the members, a shaft secured to 'the "mem ber carrying "the electromagnet, said. electromagnet havingleads-at the respectivee'ndsthereof; one lead being secured to the rotatable"membr onwhich the magnet 'is carried and"the"othei leadbeing' insulatingly supported in the shaft? terminating in a current contactor "button upon 1 thfi" axis of *the shaft, a 'current'."su'pplyi brush mounted in axial alignment along the axis" of the j shaft having resilient current" conducting and contacting relation with" the contactor button, a. second current supply brushm'ounted in radial relation-to the shaft having resilienticurrentg conducting and contacting relation with the outer.

"periphery of the shaft radially outwardly dis-i posed of the other brushyand a stationary bracket journalled'on the shaft supporting the. brushes for axial; movement therein relative to, their 'res'pec,- tiv e axes HOWARD J. FINDLEE.

EFERENCES-turn..-

The following references are of record in the file of this patent:

Number Name Date 1,720,619 Baldwin 31-- July9,"1929-W 2,038,059. Reichel; "Aprl21; 1936 7 2,068,189 Meadz." *Jari'l9fl93'll: 2,l09,991'-* French "Marl" 1,1938. 2,360,191 5 r Beach Oct.'10, 1944 2,4 01,187 Prince May 28,1946

Number Country Date,

w ize aad 1 2. 

